The present invention relates generally to a cut-off device for breaking the connection between a power rectifier connected to a supply line leading to a load when the power rectifier malfunctions.
Cut-off devices for power rectifiers are known in the art. These devices are typically used in conjunction with a plurality of power rectifiers connected in parallel to a single supply line leading to a load having considerable current requirements. If a fault occurs in one of the rectifiers, the cut-off device is used to prevent current flowing in the supply line from flowing into the faulty rectifier and causing severe disturbances in the common supply voltage, i.e., the bus output.
At the present time, cut-off devices usually include an arrangement of diodes connected to the output of the rectifier (on either the positive or the negative terminal) to prevent this problem from occurring. If current becomes inverted as a result of a fault in a rectifier, the diodes enter a cut-off state and prevent current from flowing into the faulty rectifier.
While these known devices have the advantage of rapid response speed, they also have high dissipation rates when high currents are present. This not only reduces efficiency, but also makes it necessary to provide efficient heat sinks, in thermal contact with the diodes, to remove the heat generated by the Joule effect in the diodes during the normal operation of the rectifier.
Thus, there is a need for a more efficient cut-off device for a power rectifier that does not have the drawbacks of conventional cut-off devices.